Molds are widely used for manufacturing optical articles, such as light guide plates, lenses, and etc. Referring to FIG. 8, a typical mold 1 includes a first mold part 2, a second mold part 3, and a bushing 4 for receiving the first mold part 2 and the second mold part 3 therein. The molding surface of the first mold part 2 and the second mold part 3, and the inner surface of the bushing 4 cooperatively define a molding chamber 5.
In a typical glass lens molding process, the second mold part 3 is inserted into the bushing 4, and then a glass preform 6 is placed on the molding surface of the second mold part 3. The first mold part 2 is then inserted into the bushing 4 to press (i.e. force the glass to a certain shape) the glass preform 6 by an oil press 7, thereby obtaining a predetermined glass lens.
However, during design or assembly, discrepancies may occur between the position of the first mold part 2 and the position of the second mold part 3, resulting corresponding discrepancies in the finished article.
Therefore, a mold that overcomes the above-described problems is desired.